A power converter includes: an input-side converter including a positive-side capacitor arranged between a positive terminal and a neutral terminal as well as a negative-side capacitor arranged between a negative terminal and the neutral terminal; a first converter connected to the positive terminal and the neutral terminal; and a second converter, an input side thereof being connected to the negative terminal and the neutral terminal, with the input side also being connected in series to the first converter, and the output side thereof being connected in parallel to the first converter.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A power converter, comprising: an input-side converter circuit including: a DC output terminal section having a positive terminal, a negative terminal, and a neutral terminal; a positive-side capacitor, one end of which is connected to the positive terminal through a positive node and another end of which is connected to the neutral terminal through a neutral node; and a negative-side capacitor, one end of which is connected to the neutral terminal through said neutral node and another end of which is connected to the negative terminal through a negative node; a first output-side converter circuit having first and second input terminals, the first input terminal being connected to the positive node and the second input terminal being connected to the neutral node, the first output-side converter circuit further having two output terminals, respectively connected to two main output terminals of the power converter; and a second output-side converter circuit having first and second input terminals, the first input terminal being connected to the neutral node and the second input terminal being connected to the negative node so that the first and second input terminals of the first output-side converter circuit and the first and second input terminals of the second output-side converter circuit are connected in series, the second output-side converter circuit further having two output terminals, respectively connected to the two main output terminals of the power converter so that the two output terminals of the first output-side converter circuit and the two output terminals of the second output-side converter circuit are connected in parallel to each other.
2. The power converter according to claim 1 , wherein the power converter is configured such that a current having a ripple component flows from the positive terminal to the first input terminal of the first output-side converter circuit and a current having a ripple component flows from the second input terminal of the second output-side converter circuit to the negative terminal, and wherein the power converter is configured such that a current in which said ripple components are cancelled out with each other at least partially flows between the two main output terminals of the power converter through the load when the two main output terminals are connected to the load.
3. The power converter according to claim 1 , wherein the two output terminals of the first output-side converter circuit are positive and negative output terminals, respectively, and the two output terminals of the second output-side converter circuit are positive and negative output terminals, respectively, and wherein the positive output terminal of the first output-side converter circuit and the positive output terminal of the second output-side converter circuit are connected to each other to constitute a positive output terminal of the power converter, and the negative output terminal of the first output-side converter circuit and the negative output terminal of the second output-side converter circuit are connected to each other to constitute a negative output terminal of the power converter.
4. The power converter according to claim 1 , wherein the first output-side converter circuit is controlled such that a first adjusted current flows from the positive node to the first input terminal of the first output-side converter circuit, said first adjusted current having a ripple component corresponding to a ripple component of a first current that flows from the positive terminal to the positive node, and wherein the second output-side converter circuit is controlled such that a second adjusted current flows from the second input terminal of the second output-side converter circuit to the negative node, said second adjusted current having a ripple component corresponding to a ripple component of a second current that flows from the negative node to the negative terminal.
5. The power converter according to claim 4 , further comprising: an output voltage detector that detects an output voltage between the two main output terminals of the power converter; a first adjusted current detector that detects the first adjusted current; a second adjusted current detector that detects the second adjusted current; a ripple component obtaining unit that obtains the ripple component of the first current and the ripple component of the second current; and a controller that controls the first output-side converter circuit and the second output-side converter circuit on the basis of the detected output voltage, the detected first adjusted current, the detected second adjusted current, the obtained ripple component of the first current, and the obtained ripple component of the second current so that the ripple component of the first adjusted current corresponds to the ripple component of the first current that flows from the positive terminal to the positive node and so that the ripple component of the second adjusted current corresponds to the ripple component of the second current that flows from the negative node to the negative terminal.
6. The power converter according to claim 5 , wherein the controller adds the obtained ripple component of the first current to a base current command value to generate a first current command value for the first output-side converter circuit and generates a first control signal for causing the first adjusted current to match the first current command value, and subtracts the obtained ripple component of the first current from the base current command value to generate a second current command value for the second output-side converter circuit and generates a second control signal for causing the second adjusted current to match the second current command value.
7. The power converter according to claim 5 , wherein the ripple component obtaining unit includes an AC input detector that detects an input voltage and an input current of an AC input power that is inputted to the input-side converter circuit, and calculates the ripple component of the first current and the ripple component of the second current on the basis of the input voltage and the input current detected by the AC input detector.
8. The power converter according to claim 5 , wherein the ripple component obtaining unit includes a first voltage detector that detects a first voltage across the positive-side capacitor and a second voltage detector that detects a second voltage across the negative-side capacitor, and calculates the ripple component of the first current and the ripple component of the second current on the basis of the first voltage and the second voltage detected by the first voltage detector and the second voltage detector, respectively.
9. The power converter according to claim 5 , wherein the ripple component obtaining unit includes a first current detector that detects the first current and a second current detector that detects the second current, and determines the ripple component of the first current and the ripple component of the second current on the basis of the first current and the second current detected by the first current detector and the second current detector, respectively.
10. The power converter according to claim 5 , wherein the controller controls the first output-side converter circuit and the second output-side converter circuit to generate the first adjusted current and the second adjusted current such that a current flowing across the positive-side capacitor between the positive node and the neutral node does not include the ripple component of the first current flowing from the positive terminal to the positive node or contains a substantially reduced amount of the ripple component of the first current, and such that a current flowing through the negative-side capacitor between the neutral node and the negative node does not include the ripple component of the second current flowing from the negative node to the negative terminal or contains a substantially reduced amount of the ripple component of the second current.
11. A power converter, comprising: an input-side converter circuit configured to receive an AC power input, the input-side converter including: a DC output terminal section having a positive terminal, a negative terminal, and a neutral terminal; a positive-side capacitor, one end of which is connected to the positive terminal through a positive node and another end of which is connected to the neutral terminal through a neutral node; and a negative-side capacitor, one end of which is connected to the neutral terminal through said neutral node and another end of which is connected to the negative terminal through a negative node; a first output-side converter circuit having first and second input terminals, the first input terminal being connected to the positive node and the second input terminal being connected to the neutral node, the first output-side converter circuit further having two output terminals, respectively connected to two main output terminals of the power converter; a second output-side converter circuit having first and second input terminals, the first input terminal being connected to the neutral node and the second input terminal being connected to the negative node so that the first and second input terminals of the first output-side converter circuit and the first and second input terminals of the second output-side converter circuit are connected in series, the second output-side converter circuit further having two output terminals, respectively connected to the two main output terminals of the power converter so that the two output terminals of the first output-side converter circuit and the two output terminals of the second output-side converter circuit are connected in parallel to each other; and a controller that controls the first output-side converter circuit and the second output-side converter circuit, wherein the controller controls the first output-side converter circuit such that a first adjusted current flows from the positive node to the first input terminal of the first output-side converter circuit, said first adjusted current having a ripple component corresponding to a ripple component of a first current that flows from the positive terminal to the positive node so that a current flowing across the positive-side capacitor between the positive node and the neutral node does not include the ripple component of the first current or contains a substantially reduced amount of the ripple component of the first current, and wherein the controller controls the second output-side converter circuit such that a second adjusted current flows from the second input terminal of the second output-side converter circuit to the negative node, said second adjusted current having a ripple component corresponding to a ripple component of a second current that flows from the negative node to the negative terminal so that a current flowing through the negative-side capacitor between the neutral node and the negative node does not include the ripple component of the second current or contains a substantially reduced amount of the ripple component of the second current.
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April 5, 2019
July 14, 2020
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